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Water environment
About: Water environment is a research topic. Over the lifetime, 13384 publications have been published within this topic receiving 125138 citations.
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16 Dec 2009-Journal of Environmental Science and Health Part B-pesticides Food Contaminants and Agricultural Wastes
TL;DR: Oxytetracycline photolysis was found to be very fast with a degradation rate constant at 3.61 ± 0.06 day− 1, which is comparable to that of hydrolysis at 60°C, implying that oxytetrACYcline become more vulnerable to sunlight irradiation after chelating with Ca2 +.
Abstract: Oxytetracycline ((2Z,4S,4aR,5S,5aR,6S,12aS)-2-(amino-hydroxy-methylidene)-4-dimethylamino-5,6,10,11,12a-pentahydroxy-6-methyl-4,4a,5,5a-tetrahydrotetracene-1,3,12-trione) is a member of tetracycline antibiotics family and is widely administered to farm animals for the purpose of therapeutical treatment and health protection. Increasing attention has been paid to the environmental fate of oxytetracycline and other veterinary antibiotics with the occurrence of these antibiotics in the environment. The hydrolysis and photolysis degradation of oxytetracycline was investigated in this study. Oxytetracycline hydrolysis was found to obey the first-order model and similar rate constant values ranging from 0.094 +/- 0.001 to 0.106 +/- 0.003 day(-1) were obtained at different initial concentration ranging from 10 to 230 microM. Solution pH and temperature were shown to have remarked effects on oxytetracycline hydrolysis. The hydrolysis in pH neutral solution appeared to be much faster than in both acidic and alkaline solutions. Oxytetracycline half-life decreased from 1.2 x 10(2) to 0.15 day with the increasing temperature from 4 +/- 0.8 to 60 +/- 1 degrees C. The presence of Ca(2+) made oxytetracycline hydrolytic degradation kinetics deviate from the simple first-order model to the availability-adjusted first-order model and greatly slowed down the hydrolysis. Oxytetracycline photolysis was found to be very fast with a degradation rate constant at 3.61 +/- 0.06 day(-1), which is comparable to that of hydrolysis at 60 degrees C. The presence of Ca(2+) accelerated oxytetracycline photolysis, implying that oxytetracycline become more vulnerable to sunlight irradiation after chelating with Ca(2+). The photolysis may be the dominant degradation pathway of oxytetracycline in shallow transparent water environment.
119 citations
TL;DR: It is found that the improvement of CCD could attribute to both the sufficient water protection efforts and the maintaining sustainable speed and scale of socioeconomic development patterns, and the effective and feasible regulatory measures should be prioritized when adjusting coordination development during decision-making.
119 citations
TL;DR: Investigation of the occurrence and fate of SMCs in sewage treatment plants (STPs) and surface waters found that biological treatment processes had a greater SMCs removal effect than chemical treatment, filtration and disinfection processes.
119 citations
TL;DR: Grand Canonical Monte Carlo (GCMC) and molecular dynamics (MD) simulation results indicated that surface adsorption was the exclusive mechanism for the Adsorption of pesticides on microplastics, and the final adsorptive configurations revealed that there were complex interactions between the pesticide molecules and the C, H atoms in PE molecules.
118 citations
TL;DR: In this article, the first step of SO 4 · - / · hydroxyl radicals-initiated oxidation reactions toward 19 POCs were investigated using density functional theory (DFT) in order to explore and compare the reactivity of pOCs with two free radicals in the aqueous phase.
117 citations